An Act relative to combined sewer overflows

This bill amends Massachusetts state law to ban untreated combined sewer overflows in the Massachusetts Water Resources Authority service areas by January 1, 2035. It specifically targets systems that mix household and stormwater in a single pipe, requiring that any discharge during a 25-year storm event must include basic treatment to remove solids and deactivate bacteria. To enforce this, the Department of Environmental Protection must create regulations within 18 months that define what constitutes a 25-year storm event and establish treatment standards that can be updated as climate conditions and technology evolve. The law directly affects municipalities and treatment facilities within the specified service areas, ensuring that wastewater released into Commonwealth waters meets minimum safety standards.